Brooke Army Medical Ctr, San Antonio, TXTufts School of MedicineUTHSCSA, San Antonio, TXUTHSCSA

Introduction:

Established cardiovascular (CV) risk factors are limited in their ability to predict CV events and mortality in RA. Carotid ultrasound may improve upon the CV risk factors as a tool to predict CV events in RA. However, because of the strong effect of age on CV disease, the predictive ability of ultrasound may be blunted if it is applied to all age groups. We examined the ability of carotid ultrasound to predict acute coronary syndromes (ACS) and CV mortality in different age groups in an RA cohort.

Patients and Methods:

We studied patients with RA who were free of CV disease. We imaged the carotid arteries for plaque and intima-media thickness (IMT) using high-resolution ultrasound and then followed patients prospectively until they either developed an acute coronary syndrome (ACS), died from CV causes, or reached a censoring date. ACS were defined as unstable angina, myocardial infarction, cardiac arrest, or death due to ischemic heart disease. CV death was defined by mention of a CV cause in the death certificate. We used logistic regression to examine the association of carotid ultrasound with ACS or CV death in tertiles of the cohort's age distribution, adjusting for gender, CV risk factors and the erythrocyte sedimentation rate (ESR).

Results:

We followed 599 RA patients for 3,085 person-years for ACS, and 6,525 person-years for CV mortality. We observed 66 new ACS, for an incidence of 2.1 per 100 person-years (95% CI 1.7, 2.7) and 120 CV deaths, for a CV mortality rate of 1.8 per 100 person-years (1.5, 2.1). The strength of association between plaque and ACS or CV death varied between cohort's age strata (Table). These findings did not change appreciably with adjustment for gender, CV risk factors or the ESR. Similar results were obtained with the IMT.

Events

Events

Age

Patients

ACS

CV death

For ACS

For CV Death

18 to 53

282

14

8

4.13 (1.72, 9.88)

3.87 (1.32, 11.31)

54 to 64

202

23

28

3.12 (1.02, 9.48)

2.36 (0.91, 6.07)

65 to 91

115

29

84

1.46 (0.38, 5.53)

1.41 (0.44, 4.49)

Conclusion:

The ability of carotid ultrasound to predict CV events in RA varies with age. Plaque and IMT are most strongly associated with CV outcomes in younger RA patients. These findings may have implications for the early identification of patients at risk for CV events in RA.